PHP Candidate Test

README.md

Test-driven development exercise

Instructions

Complete implementation of the file Context.php class to ensure ContextTest.php test case will pass.

Context.php

<?php

/**
 * Context objects aims to be used as a small bucket of mixed data. 
 * This class provide methods to define and retrieve these data 
 * identified by a Key.
 */
class Context {

    /* @var array internal storage of Context variables */
    protected $_data = array();

    /**
     * Get a value from internal storage _data.
     * If the stored value is a Callable, this method should 
     * execute the Callable before returning the computed value.
     *
     * @param string $name Name of the data to retrieve
     * @return mixed Value retrieved, NULL if the key doesn't exists
     * @see http://php.net/callable
     */
    function get($name)
    {
        // [code here]        
    }

    /**
     * Set a value to the internal storage _data.
     *
     * @param string $name Name of the data we want to set
     * @param mixed Variable we want to set
     */
    function set($name, $value = null)
    {
        // [code here]
    }

    /**
     * Test if a key is defined
     * @discussion NULL values are considered has non-existing
     * @return bool
     */
    function has($name)
    {
        return isset($this->_data[$name]);
    }
}

ContextTest.php

<?php

// include_once __DIR__."/Context.php";

class ContextTest extends PHPUnit_Framework_TestCase
{
    /**
     * @var Context
     */
    var $obj;

    public function setUp()
    {
        parent::setUp();

        $this->obj = new Context();
    }

    public function tearDown()
    {
        parent::tearDown();

        $this->obj = null;
    }

    public function test_basic() {

        $this->assertFalse($this->obj->has("key"));

        $this->obj->set('key', "value");

        $this->assertTrue($this->obj->has("key"));

    }

    public function test_unset() {

        $this->obj->set('key', "value");
        $this->assertTrue($this->obj->has("key"));

        $this->obj->set('key', null);
        $this->assertFalse($this->obj->has("key"));

    }

    public function test_set() {

        $this->obj->set('key1', "value");
        $this->obj->set(array('key2' => "value"));

        $this->assertTrue($this->obj->has("key1"));
        $this->assertTrue($this->obj->has("key2"));

    }

    public function test_get() {

        $this->obj->set('key', "value");

        $this->assertNull($this->obj->get("key2"));
        $this->assertNotNull($this->obj->get("key"));
        $this->assertEquals("value", $this->obj->get("key"));

    }

    public function test_callback() {

        $this->obj->set('key', function() { return "value"; });

        $this->assertTrue($this->obj->has("key"));
        $this->assertEquals("value", $this->obj->get("key"));

    }

    public function test_get_function_name() {

        $this->obj->set('username', 'max');

        $this->assertTrue($this->obj->has("username"));
        $this->assertEquals("max", $this->obj->get("username"));

    }

    public function test_callback_called_once() {

        $Mock = $this->getMockBuilder('StdClass')
            ->setMethods(array('__invoke'))
            ->getMock();
        // ensure __invoke() is called exactly 1 time
        $Mock->expects($this->once())
            ->method('__invoke')
            ->will($this->returnValue(1));

        $this->obj->set('key', $Mock);
        $this->assertEquals(1, $this->obj->get("key"));
        $this->assertEquals(1, $this->obj->get("key"));

        $this->obj->set('key', null);
        $this->assertFalse($this->obj->has("key"));
        $this->assertNull($this->obj->get("key"));

    }

    public function test_context() {

        $this->obj->set('key1', function() { return "hello"; });
        $this->obj->set('key4', function($ctx) { return strtoupper($ctx->get('key3')); });
        $this->obj->set('key3', function($ctx) { return $ctx->get('key1').$ctx->get('key2'); });
        $this->obj->set('key2', function() { return "world"; });

        $this->assertEquals("HELLOWORLD", $this->obj->get('key4'));
    }

    public function test_bulk_context() {

        $this->obj->set(array(
            'key1' => function() { return "hello"; },
            'key4' => function($ctx) { return strtoupper($ctx->get('key3')); },
            'key3' => function($ctx) { return $ctx->get('key1') . $ctx->get('key2'); },
            'key2' => function() { return "world"; }
        ));

        $this->assertEquals("HELLOWORLD", $this->obj->get('key4'));
    }

}